Cancer chemoprevention by dietary phytochemicals is particularly attractive for their potential low toxicity and for their ability to modulate a plethora of signal transduction pathways in biological processes associated with cancer. Olive oil, a major component of the Mediterranean diet, is an abundant source of phenolic compounds. Olive oil production is associated with the generation of waste material, termed ‘olive mill wastewaters’ (OMWW), that have been reported to be enriched in polyphenols. Here we investigated whether the use of purified extracts from OMWW (A009) might be effective in exerting chemopreventive activities in three different prostate cancer (PCa) cell lines (PC-3, DU-145, LNCap) in vitro.
The SANIST platform, based on the Surface-Activated Chemical Ionization/Electrospray Ionization mass spectrometry (SACI/ESI-MS) was used to determine polyphenol content A009. Chemopreventive activity of A009 was tested by proliferation assays and functional study for cell adhesion, migration and invasion. Molecular and biochemical studies were performed to investigate signalling involved in chemopreventive properties of A009, by real-time PCR and western blotting.
Mass spectrometry analysis revealed that hydroxytyrosol (HyT) was the major component of A009 our extracts and used as a reference compound to test A009 chemopreventive properties in vitro. A009 significantly reduced PCa cell viability up to 96 hours in all cell lines investigated, in a similar manner that HyT. A009 inhibited PCa cell adhesion, migration, invasion and sprouting. Molecularly, we found the PCa cell line treatments with the A009 purified extracts resulted in inhibition of the IL-6/STAT3 pathway, along with reduced secretion of immune suppressive (IL-10) and pro-angiogenic (CXCL8, CXCL12) factors.
Our results suggest that A009 extracts show promising chemopreventive properties on PCa
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Azienda Agricola Fattoria La Vialla, Castiglinfibocchi, Arezzo, Italia
All authors have declared no conflicts of interest.